Broadcast Wave (BWF)

Broadcasters and film crews had a problem with WAV: the file knew what it contained but not where it came from or when it was recorded. The European Broadcasting Union fixed that in 1997 by adding a bext chunk to the RIFF structure. It holds a description, the originator, the date and time, and most importantly TimeReference — the number of samples since midnight at which the file starts.

That one field is why the format endures. A location sound recorder can hand over hundreds of files and the editor can drop each one into place against the picture without listening to any of them. Because the base is plain WAV, software that ignores the metadata still plays the file. Later revisions added UMIDs and loudness values, and RF64 handles files beyond 4 GB.